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Abstract:

Apparatus, process and article for treating an aqueous solution containing
a chemical contaminant. The process includes contacting an aqueous
solution containing a chemical contaminant with an aggregate composition
comprising an insoluble rare earth-containing compound to form a solution
depleted of chemical contaminants. The insoluble rare earth-containing
compound can include one or more of cerium, lanthanum, or praseodymium. A
suitable insoluble cerium-containing compound can be derived from a
cerium carbonate, cerium oxalate and/or a cerium salt. The aggregate
composition can include more than 10.01% by weight of the insoluble rare
earth-containing compound, and in a particular embodiment consists
essentially of one or more cerium oxides, and optionally a binder and/or
flow aid. Although intended for a variety of fluid treatment
applications, such applications specifically include removing or
detoxifying chemical contaminants in water.

Claims:

1. A process for treating an aqueous solution containing a chemical
contaminant, the process comprising:contacting an aqueous solution
containing a chemical contaminant with an aggregate composition
comprising an insoluble rare earth-containing compound to form an aqueous
solution depleted of the chemical contaminant.

2. The process of claim 1, further comprising one or more of the steps
of:separating the aqueous solution depleted of the chemical contaminant
from the aggregate composition; andsensing the aqueous solution depleted
of chemical contaminant; andevaporating residual aqueous solution from
the aggregate composition; andintermittently replacing the aggregate
composition.

3. The process of claim 1, wherein the aqueous solution contacts the
composition at a temperature less than about 100.degree. C.

4. The process of claim 1, wherein the aqueous solution contacts the
composition at a temperature above about 100.degree. C. and at a pressure
adequate to maintain at least a portion of the aqueous solution in a
liquid phase.

5. The process of claim 1, wherein the aqueous solution is contacted with
the aggregate composition by one or more of:flowing the aqueous solution
through the aggregate composition;distributing the aggregate composition
over the surface of the aqueous solution; andsubmerging a fluid permeable
container enclosing the aggregate composition in the aqueous solution.

6. The process of claim 1, wherein the aggregate composition is disposed
in a container and the aqueous solution contacts the aggregate
composition by flowing through the composition.

7. The process of claim 6, wherein the container is adapted to be
removable and the process further comprises intermittently replacing the
removable container.

8. The process of claim 1, wherein the aggregate composition comprises a
flowable particulate disposed in one or more of a fixed bed, fluidized
bed, stirred tank and filter.

9. The process of claim 1, wherein the insoluble rare earth-containing
compound comprises one or more of cerium, lanthanum, or praseodymium.

10. The process of claim 9, wherein the insoluble rare earth-containing
compound comprises a cerium-containing compound derived from one or more
of thermal decomposition of a cerium carbonate, decomposition of a cerium
oxalate and precipitation of a cerium salt.

12. The process of claim 10, wherein the aggregate composition consists
essentially of one or more cerium oxides, and optionally, one or more of
a binder and flow aid.

13. The process of claim 1, wherein the aggregate composition comprises
more than 10.01% by weight of the insoluble rare earth-containing
compound

14. The process of claim 1, wherein the insoluble rare earth-containing
compound comprises particulates having a mean surface area of at least
about 1 m2/g.

15. The process of claim 1, wherein the insoluble rare earth-containing
compound comprises particulates having a mean particle size of greater
than about 23 nm.

16. The process of claim 1, wherein the chemical contaminant comprises one
or more of an organosulfur agent, an organophosphorous agent or a mixture
thereof.

17. The process of claim 1, wherein the aggregate composition comprises
aggregated particulates having a mean aggregate size of at least about 1
μm.

18. An apparatus for treating an aqueous solution containing a chemical
contaminant, the apparatus comprising:a container having a fluid flow
path for an aqueous solution; andan aggregate composition disposed in the
fluid flow path, the aggregate composition comprising an insoluble rare
earth-containing compound for removing or detoxifying a chemical
contaminant in the aqueous solution.

19. The apparatus of claim 18, further comprises one or more of:a filter
disposed downstream of the composition; anda visual indicator for
indicating when the composition should be replaced; anda sensor for
sensing an effluent flowing out of the container.

20. The apparatus of claim 18, wherein the container is adapted to be
removed from the apparatus, the container having an inlet and an outlet
with each of the inlet and the outlet adapted to be sealed when removed
from the apparatus.

21. The apparatus of claim 18, wherein the container comprises one or more
of a fixed bed, fluidized bed, stirred tank or filter.

23. The apparatus of claim 18, wherein the insoluble rare earth-containing
compound comprises one or more of cerium, lanthanum, or praseodymium.

24. The apparatus of claim 23, wherein the insoluble rare earth-containing
compound comprises a cerium-containing compound derived from one or more
of thermal decomposition of a cerium carbonate, decomposition of a cerium
oxalate and precipitation of a cerium salt.

26. The apparatus of claim 25, wherein the aggregate composition consists
essentially of one or more cerium oxides, and optionally, one or more of
a binder and flow aid.

27. The apparatus of claim 18, wherein the aggregate composition comprises
more than 10.01% by weight of the insoluble rare earth-containing
compound

28. The apparatus of claim 18, wherein the insoluble rare earth-containing
compound comprises particulates having a mean surface area of at least
about 1 m2/g.

29. The apparatus of claim 18, wherein the insoluble rare earth-containing
compound is a particulate having a mean particle size of greater than
about 25 nm.

30. The apparatus of claim 18, wherein the aggregate composition comprises
aggregated particulates having a mean particle size of at least about 1
μm.

31. An article comprising:a container having one or more walls defining an
interior space; anda flowable aggregate composition disposed in the
interior space, the aggregate composition comprising an insoluble rare
earth-containing compound;wherein the container bears instructions for
use of the flowable aggregate composition to treat an aqueous solution
containing a chemical contaminant.

Description:

FIELD OF THE INVENTION

[0001]The invention relates generally to the field of fluid and solution
treatment, and primarily to processes and apparatuses for treating
aqueous solutions. In its more particular aspects, the invention relates
to processes and apparatuses for removing or de-toxifying chemical
contaminants in aqueous solutions.

BACKGROUND OF THE INVENTION

[0002]In light of the recent rise in terrorism, governments around the
world have become increasingly concerned about the effects of chemical
warfare agents, industrial chemicals and other highly toxic materials.
Because nations stockpile such materials for both industrial uses and as
warfare agents, such chemical contaminants represent a potential hazard
to armed forces and civilian populations alike due to both direct
exposure and through environmental contamination. As a consequence,
chemical contamination of ground water and other sources of potable water
is a primary concern for both the military and municipal governments and
utility districts.

[0003]Commonly known chemical warfare agents include organosulfur-based
compounds such as 2,2'-Dichloromethyl sulfide (HD, mustard, mustard gas,
S mustard or sulfur mustard), which are known as "blister" or
"blistering" agents and can be lethal in high doses. Other chemical
warfare agents include organophosphorus-based ("OP") compounds, such as
O-ethyl S-(2-diisopropylamino)ethyl methylphosphonothiolate (VX),
2-Propyl methylphosphonofluoridate (GB or Sarin), and
3,3'-Dimethyl-2-butyl methylphosphonofluoridate (GD or Soman), which are
commonly referred to as "nerve" agents because they attack the central
nervous system and can cause paralysis and potentially death in a short
period of time. Other chemical contaminants include certain industrial
chemicals, insecticides and pesticides such as parathion, paraoxon and
malathion, which can also have harmful effects.

[0004]Methods and materials for decontaminating surfaces exposed to
chemical warfare agents are known in the art. Yang et al.,
"Decontamination of Chemical Warfare Agents", Chem Rev. Vol. 92, pp
1729-1743 (1992). These decontaminant solutions and materials tend to
function by chemically reacting with the toxic agents, adsorbing the
toxic agents, of some combination of the two. Early chemical-based
decontaminants included bleaching powders, potassium permanganate,
superchlorinated bleaches, and solutions containing alkali salts such as
sodium carbonate, sodium hydroxide and potassium hydroxide. Many of these
compositions tend to have certain undesirable properties, including
corrosiveness, flammability and toxicity. Further, the application of
such compositions or solution containing such compositions can require
substantial scrubbing to ensure removal and destruction of the chemical
warfare agent.

[0005]Another chemical-based decontaminant solution, which was adopted by
the U.S. military for decontaminating a variety of agents, is
Decontamination Solution 2 (DS2). DS2 contains 70% diethylenetriamine,
28% ethylene glycol monpmethyl ether and 2% sodium hydroxide. However, it
has been reported that DS2 will spontaneously ignite upon contact with
hypochlorites and hypochlorite-based decontaminants and may cause
corrosion to aluminum, cadmium, tin, and zinc after prolonged contact.

[0006]Additionally, some chemical-based decontaminants degrade upon
exposure to water and carbon dioxide, requiring that the solution be
prepared and used contemporaneously with its use.

[0007]A sorbent-based decontamination material used as an alternative to
DS2 is the XE555 resin (Ambergard® Rohm & Haas Company, Philadelphia,
Pa.). XE555 has reportedly been used by the military for immediate
decontamination applications wherein the objective is to remove the toxic
agents from the contaminated surface as rapidly as possible. While
effective at removing chemical warfare agents, XE555 does not possesses
sufficient reactive properties to neutralize the adsorbed agent(s). Thus,
after use, XE555 itself presents an ongoing threat from off-gassing
toxins and/or vapors adsorbed by the resin.

[0008]Much of the research to date concerning chemical warfare agents and
other toxic materials has focused on the immediate need to decontaminate
surfaces that have been exposed to the agent. However, these methods and
compositions are designed for decontaminating vehicles, equipment,
personnel and the like, and are not well suited or effective at removing
or detoxifying chemical contaminants in aqueous solutions. One
composition that is reportedly capable of filtering chemical nerve agents
from water is activated charcoal. Similarly, a class of enzymes referred
to as organophosphate anhydrolases has been reported to catalyze the
hydrolysis of many G-type chemical warfare nerve agents, specifically,
sarin, soman, and GF (o-cyclohexyl methylphosphono fluoridate).

[0010]In one embodiment, the invention provides a process for treating an
aqueous solution containing a chemical contaminant. The process includes
contacting an aqueous solution containing a chemical contaminant with an
aggregate composition comprising an insoluble rare earth-containing
compound to form an aqueous solution depleted of the chemical
contaminant.

[0011]Optionally, the process can include one or more of the steps of
separating the aqueous solution depleted of the chemical contaminant from
the aggregate composition, sensing the aqueous solution depleted of
chemical contaminant, evaporating residual aqueous solution from the
aggregate composition, and intermittently replacing the aggregate
composition. When the composition is disposed in a removable container,
the process can optionally include intermittently replacing the
container.

[0012]The chemical contaminant can comprise one or more of an organosulfur
agent, an organophosphorous agent or a mixture thereof. The aqueous
solution containing the chemical contaminant contacts the composition at
a temperature above the triple point for the aqueous solution. In some
cases, the aqueous solution contacts the composition at a temperature
less than about 100° C., such as ambient temperatures. In other
cases, the aqueous solution contacts the composition at a temperature
above about 100° C. and at a pressure sufficient to maintain at
least a portion of the aqueous solution in a liquid phase. In still other
cases, the aqueous solution contacts the composition under supercritical
conditions of temperature and pressure for the aqueous solution.

[0013]The aqueous solution can contact the aggregate composition by one or
more of flowing the aqueous solution through the aggregate composition,
distributing the aggregate composition over the surface of the aqueous
solution, and submerging a fluid permeable container enclosing the
aggregate composition in the aqueous solution. The aggregate composition
can be disposed in a container and the aqueous solution can flow through
the composition. The composition can be disposed in one or more of a
fixed bed, fluidized bed, stirred tank and filter. The composition can
also be disposed in a removable container and the process can include the
step of intermittently replacing the removable container.

[0014]The aggregate can include more than 10.01% by weight of the
insoluble rare earth-containing compound. The insoluble rare
earth-containing compound can include one or more of cerium, lanthanum,
or praseodymium amongst other rare earth-containing compounds. When the
insoluble rare earth-containing compound comprises a cerium-containing
compound, the cerium-containing compound can be derived from one or more
of thermal decomposition of a cerium carbonate, decomposition of a cerium
oxalate and precipitation of a cerium salt. The insoluble rare
earth-containing compound can include a cerium oxide, and in a particular
embodiment, the aggregate composition can consist essentially of one or
more cerium oxides, and optionally, one or more of a binder and a flow
aid.

[0015]The aggregate composition can comprise aggregated particulates
having a mean aggregate size of at least about 1 μm. When the
insoluble rare earth-containing compound is in the form of a particulate,
the particulate can have a mean particle size of at least about 25 nm.
When the insoluble rare earth-containing compound is in the form of a
particulate, the particulate can have a mean surface area of at least
about 1 m2/g.

[0016]In another embodiment, the invention provides an apparatus for
treating an aqueous solution containing a chemical contaminant. The
apparatus includes a container having a fluid flow path for an aqueous
solution and an aggregate composition disposed in the fluid flow path.
The aggregate composition comprises an insoluble rare earth-containing
compound for removing or detoxifying a chemical contaminant in the
aqueous solution. The apparatus can optionally include one or more of a
filter disposed downstream of the aggregate composition, a visual
indicator for indicating when the aggregate composition should be
replaced, and a sensor for sensing an effluent flowing out of the
container.

[0017]The container can include one or more of a fixed bed, fluidized bed,
stirred tank or reactor, and filter. In some cases, the container is
adapted to be removed from the apparatus, such a container having an
inlet and an outlet with each of the inlet and the outlet adapted to be
sealed when removed from the apparatus. In other embodiments, the
container has a fluid permeable outer wall encapsulating the aggregate
composition.

[0018]The aggregate can include more than 10.01% by weight of the
insoluble rare earth-containing compound. The insoluble rare
earth-containing compound can include one or more of cerium, lanthanum,
or praseodymium amongst other rare earth-containing compounds. When the
insoluble rare earth-containing compound comprises a cerium-containing
compound, the cerium-containing compound can be derived from one or more
of thermal decomposition of a cerium carbonate, decomposition of cerium
oxalate, and precipitation of a cerium salt. The insoluble rare
earth-containing compound can include a cerium oxide, and in a particular
embodiment, the aggregate composition can consist essentially of one or
more cerium oxides, and optionally, one or more of a binder and flow aid.

[0019]The aggregate composition can comprise aggregated particulates
having a mean particle size of at least about 1 μm. In some
embodiments, the aggregate composition comprises particulates of the
insoluble rare earth-containing compound having a mean surface area of at
least about 1 m2/g. When the insoluble rare earth-containing
compound is in the form of a particulate, the particulate can have a mean
particle size of at least about 25.

[0020]In another embodiment, the invention provides an article comprising
a container having one or more walls defining an interior space and a
flowable aggregate composition disposed in the interior space. The
container bears instructions for use of the aggregate composition to
treat an aqueous solution containing a chemical contaminant.

[0021]The aggregate can include more than 10.01% by weight of the
insoluble rare earth-containing compound. The insoluble rare
earth-containing compound can include one or more of cerium, lanthanum,
or praseodymium amongst other rare earth-containing compounds. When the
insoluble rare earth-containing compound comprises a cerium-containing
compound, the cerium-containing compound can be derived from one or more
of thermal decomposition of a cerium carbonate, decomposition of a cerium
oxalate and precipitation of a cerium salt. The insoluble rare
earth-containing compound can include a cerium oxide, and in a particular
embodiment, the aggregate composition can consist essentially of one or
more cerium oxides, and optionally, one or more of a binder and flow aid.

[0022]The aggregate composition can comprise particulates having a mean
particle size of at least about 1 μm. In some embodiments, the
aggregate composition comprises particulates of the insoluble rare
earth-containing compound having a mean surface area of at least about 1
m2/g. When the insoluble rare earth-containing compound is in the
form of a particulate, the particulate can have a mean particle size of
at least about 25 nm.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023]Illustrative embodiments of the invention are described below. In
the interest of clarity, not all features of an actual embodiment are
described in this specification. It will of course be appreciated that in
the development of any such actual embodiment, numerous
implementation-specific decisions must be made to achieve the developers'
specific goals, such as compliance with system-related and
business-related constraints, which will vary from one implementation to
another. Moreover it will be appreciated that such a development effort
might be complex and time-consuming, but would nevertheless be a routine
undertaking for those of ordinary skill in the art having the benefit of
this disclosure.

[0024]As used herein, "one or more of" and "at least one of" when used to
preface several elements or classes of elements such as X, Y and Z or
X1-Xn, Y1-Yn and Z1-Zn, is intended to
refer to a single element selected from X or Y or Z, a combination of
elements selected from the same class (X1 and X2), as well as a
combination of elements selected from two or more classes (Y1 and
Zn).

[0025]It will be understood that a process, apparatus or article as
described herein can be used to treat an aqueous solution containing a
chemical contaminant, and in particular, to remove or detoxify chemical
contaminants such as blister agents, nerve agents, insecticides,
pesticides and other toxic chemical agents that may be found in such
solutions. Examples of solutions that may be effectively treated include
solutions in potable water systems, in waste water treatment systems, and
feed, process or waste streams in various industrial processes among
others. The described processes, apparatuses and articles can be used to
remove chemical contaminants from solutions having diverse volume and
flow rate characteristics and may be applied to in variety of fixed,
mobile and portable applications. While portions of the disclosure herein
describe the removal of chemical contaminants from water, and in
particular, from potable water streams, such references are illustrative
and are not to be construed as limiting.

[0026]The terminology "remove" or "removing" includes the sorption,
precipitation, conversion or detoxification of chemical contaminants
present in aqueous solutions. The term "de-toxify" or "de-toxification"
includes rendering chemical contaminant non-toxic to humans or other
animals such as for example by converting the agent into a non-toxic form
or species. The processes, apparatuses and articles of the invention are
intended to remove or detoxify chemical contaminants such that the
treated solutions meet or exceed standards for water purity established
by various organizations and/or agencies including, for example, the
American Organization of Analytical Chemists (AOAC), the World Health
Organization, and the United States Environmental Protection Agency
(EPA). Advantageously, water treated by the described processes and
apparatuses can meet such standards without the addition of bleaches or
other known detoxification agents.

[0029]In one embodiment of the invention, a process is provided for
treating an aqueous solution containing a chemical contaminant. The
process includes contacting an aqueous solution containing chemical
contaminants with an aggregate composition comprising an insoluble rare
earth-containing compound. Contact by and between the aqueous solution
and the aggregate composition removes and/or de-toxifies the chemical
contaminant to yield a solution depleted of chemical contaminants.

[0030]Aggregate compositions suitable for use in such a process, apparatus
and article as described herein comprise an insoluble rare
earth-containing compound. As used herein, "insoluble" is intended to
refer to materials that are insoluble in water, or at most, are sparingly
soluble in water under standard conditions of temperature and pressure.

[0031]The aggregate composition can comprise less than or more than 10.01
% by weight of the insoluble rare earth-containing compound. The
insoluble rare earth-containing compound can constitute more than about
11%, more than about 12% or more than about 15% by weight of the
aggregate composition. In some cases, a higher concentration of rare
earth-containing compounds may be desired. Depending on the application
and the nature of other components in the composition, the composition
can be at least about 20%, in other cases at least about 50%, in still
others at least about 75%, and in yet still others more than 95%, by
weight of an insoluble rare earth-containing compound.

[0032]The insoluble rare earth-containing compound can include one or more
of the rear earths including lanthanum, cerium, praseodymium, neodymium,
promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium
erbium, thulium, ytterbium and lutetium. In some embodiments, the
insoluble rare-earth containing compound can comprise one or more of
cerium, lanthanum, or praseodymium. Insoluble rare earth-containing
compounds are available commercially and may be obtained from any source
or through any process known to those skilled in the art. The aggregate
composition need not include a single rare earth-containing compound but
can include two or more insoluble rare earth-containing compounds. Such
compounds can contain the same or different rare earth elements and can
contain mixed valence or oxidation states. By way of example, when the
insoluble rare earth-containing compound comprises cerium, the aggregate
composition can comprise one or more cerium oxides such as CeO2 (IV)
and Ce2O3 (III).

[0033]In an embodiment where the insoluble rare earth-containing compound
comprises a cerium-containing compound, the cerium-containing compound
can be derived from precipitation of a cerium salt. In another
embodiment, an insoluble cerium-containing compound can be derived from a
cerium carbonate or a cerium oxalate. More specifically, an insoluble
cerium-containing compound can be prepared by thermally decomposing a
cerium carbonate or oxalate at a temperature between about 250° C.
and about 350° C. in a furnace in the presence of air. The
temperature and pressure conditions may be altered depending on the
composition of the cerium-containing starting materials and the desired
physical properties of the insoluble rare earth-containing compound. The
thermal decomposition of cerium carbonate may be summarized as:

Ce2(CO3)3+1/2O2→2CeO2+3CO2

The product may be acid treated and washed to remove remaining carbonate.
Thermal decomposition processes for producing cerium oxides having
various features are described in U.S. Pat. No. 5,897,675 (specific
surface areas), U.S. Pat. No. 5,994,260 (pores with uniform lamellar
structure), U.S. Pat. No. 6,706,082 (specific particle size
distribution), and U.S. Pat. No. 6,887,566 (spherical particles), and
such descriptions are incorporated herein by reference. Cerium carbonate
and materials containing cerium carbonate are commercially available and
may be obtained from any source known to those skilled in the art.

[0034]In embodiments where the insoluble rare earth-containing compound
comprises a cerium-containing compound, the insoluble cerium-containing
compound can include a cerium oxide such as CeO2. In a particular
embodiment, the aggregate composition can consists essentially of one or
more cerium oxides, and optionally, one or more of a binder and flow aid.

[0035]The insoluble rare earth-containing compound can be present in the
aggregate composition in the form of one or more of a granule, crystal,
crystallite, particle or other particulate, referred to generally herein
as a "particulate." The particulates of the insoluble rare
earth-containing compounds can have a mean particle size of at least
about 0.5 nm ranging up to about 1 μm or more. Specifically, such
particulates can have a mean particle size of at least about 0.5 nm, in
some cases greater than about 1 nm, in other cases, at least about 5 nm,
and still other cases at least about 10 nm, and in yet still other cases
at least about 25 nm. In other embodiments, the particulates can have
mean particle sizes of at least about 100 nm, specifically at least about
250 nm, more specifically at least about 500 nm, and still more
specifically at least about 1 μm.

[0036]To promote interaction of the insoluble rare earth-containing
compound with chemical contaminants in solution, the aggregate
composition can comprise aggregated particulates of the insoluble rare
earth-containing compound having a mean surface area of at least about 1
m2/g. Depending upon the application, higher surface areas may be
desired. Specifically, the aggregated particulates can have a surface
area of at least about 5 m2/g, in other cases more than about 10
m2/g, in other cases more than about 70 m2/g, in other cases
more than about 85 m2/g, in still other cases more than 115
m2/g, and in yet other cases more than about 160 m2/g. In
addition, it is envisioned that insoluble rare earth-containing
particulates with higher surface areas will be effective in the described
processes and apparatuses. One skilled in the art will recognize that the
surface area of the composition will impact the fluid dynamics of the
aqueous solution. As a result, there may be a need to balance benefits
that are derived from increased surface area with disadvantages such as
pressure drop that may occur.

[0037]Optional components that are suitable for use in the aggregate
composition can include one or more soluble rare earth-containing
compounds, secondary decontamination agents, biocidal agents, adsorbents,
flow aids, binders, substrates, and the like. Such optional components
may be included in the aggregate composition depending on the intended
utility and/or the desired characteristics of the composition.

[0038]Optional components can include one or more soluble rare
earth-containing compounds. Soluble rare earth-containing compounds can
have different activities and effects. By way of example, some soluble
rare earth-containing compounds have been recognized as having a
bacteriostatic or antimicrobial effect. Cerium chloride, cerium nitrate,
anhydrous ceric sulfate, and lanthanum chloride are described as having
such activity in "The Bacteriostatic Activity of Cerium, Lanthanum, and
Thallium", Burkes et al., Journal of Bateriology, 54:417-24 (1947).
Similarly, the use of soluble cerium salts such as cerium nitrates,
cerous acetates, cerous sulfates, cerous halides and their derivatives,
and cerous oxalates are described for use in burn treatments in U.S. Pat.
No. 4,088,754, such descriptions being incorporated herein by reference.
Other soluble rare earth-containing compounds, whether organic or
inorganic in nature, may impart other desirable properties to the
compositions and may optionally be used.

[0039]Optional decontamination agents may include materials that are
capable of removing or detoxifying chemical contaminants from various
surfaces. Non-limiting examples of decontamination agents that may be
suitable include transition metals and alkaline metals as described in
U.S. Pat. No. 5,922,926, polyoxometallates as described in U.S. Patent
Application Publication No. 2005/0159307 A1, aluminum oxides as described
in U.S. Pat. Nos. 5,689,038 and 6,852,903, quaternary ammonium complexes
as described in U.S. Pat. No. 5,859,064, zeolites as described in U.S.
Pat. No. 6,537,382, and enzymes as described in U.S. Pat. No. 7,067,294.
The descriptions of these decontamination agents in the noted references
are incorporated herein by reference.

[0040]Biocidal agents can optionally be included for targeting biological
contaminants in solution. Materials that may be suitable for use as
biocidal agents include compounds that are known to possess activity for
removing or deactivating biological contaminants, even when such
materials are present in small quantities. Such materials include but are
not limited to alkali metals, alkaline earth metals, transition metals,
actinides, and derivatives and mixtures thereof. Specific non-limiting
examples of secondary biocidal agents include elemental or compounds of
silver, zinc, copper, iron, nickel, manganese, cobalt, chromium, calcium,
magnesium, strontium, barium, boron, aluminum, gallium, thallium,
silicon, germanium, tin, antimony, lead, bismuth, scandium, titanium,
vanadium, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium,
rhodium, palladium, cadmium, indium, hafnium, tantalum, tungsten,
rhenium, osmium, iridium, platinum, gold, mercury, thallium, thorium, and
the like. Derivatives of such agents can include acetates, ascorbates,
benzoates, carbonates, carboxylates, citrates, halides, hydroxides,
gluconates, lactates, nitrates, oxides, phosphates, propionates,
salicylates, silicates, sulfates, sulfadiazines, and combinations
thereof. When the aggregate composition optionally comprises a
titanium-containing compound such as a titanium oxide, the weight ratio
of the titanium-containing compound to the insoluble rare
earth-containing compound is less than about 2:1. When the insoluble rare
earth-containing compound has been sintered to form the aggregate
composition, the composition will contain no more than two elements
selected from the group consisting of yttrium, scandium, and europium. In
an embodiment where the aggregate composition comprises an
aluminum-containing compound, the weight ratio of the aluminum-containing
compound to the insoluble rare earth-containing compound is less than
about 10:1. In an embodiment that includes a biocidal agent selected from
the group consisting of transition metals, transition metal oxides and
transition metal salts, the aggregate composition will comprise less than
about 0.01% by weight of a mixture of silver and copper metal
nanoparticles.

[0041]Other materials that may be suitable for use as biocidal agents
include organic agents such as quaternary ammonium salts as described in
U.S. Pat. No. 6,780,332, and organosilicon compounds such as are
described in U.S. Pat. No. 3,865,728. Other organic materials and their
derivatives that are known to deactivate biological contaminants may also
be used. By way of example, polyoxometalates are described in U.S. Pat.
No. 6,723,349 as being effective at removing biological contaminants from
fluids. This patent references M. T. in Heteropoly and Isopoly
Oxometalates, Springer Verlag, 1983, and Chemical Reviews, vol. 98, No.
1, pp. 1-389, 1998, as describing examples of effective polyoxometalates.
The descriptions of these organic biocidal agents in the noted references
are incorporated herein by reference.

[0042]The aggregate composition may optionally comprise one or more flow
aids. Flow aids are used in part to improve the fluid dynamics of a fluid
over or through the aggregate composition, to prevent separation of
components of the aggregate composition, prevent the settling of fines,
and in some cases to hold the aggregate composition in place. Suitable
flow aids can include both organic and inorganic materials. Inorganic
flow aids can include ferric sulfate, ferric chloride, ferrous sulfate,
aluminum sulfate, sodium aluminate, polyaluminum chloride, aluminum
trichloride, silicas, diatomaceous earth and the like. Organic flow aids
can include organic flocculents known in the art such as polyacrylamides
(cationic, nonionic, and anionic), EPI-DMA's
(epichlorohydrin-dimethylamines), DADMAC's (polydiallydimethyl-ammonium
chlorides), dicyandiamide/formaldehyde polymers, dicyandiamide/amine
polymers, natural guar, etc. When present, the flow aid can be mixed with
the insoluble rare earth-containing compound and polymer binder during
the formation of the aggregate composition. Alternatively, particulates
of the aggregate composition and of the flow aid can be mixed to yield a
physical mixture with the flow aid dispersed uniformly throughout the
mixture. In yet another alternative, the flow aid can be disposed in one
or more distinct layers upstream and downstream of the aggregate
composition. When present, flow aids are generally used in low
concentrations of less than about 20%, in some cases less than 15%, in
other cases less than 10%, and in still other cases less than about 8% by
weight of the aggregate composition.

[0043]Other optional components can include various inorganic agents
including ion-exchange materials such as synthetic ion exchange resins,
activated carbons, zeolites (synthetic or naturally occurring), minerals
and clays such as bentonite, smectite, kaolin, dolomite, montmorillinite
and their derivatives, metal silicate materials and minerals such as of
the phosphate and oxide classes. In particular, mineral compositions
containing high concentrations of calcium phosphates, aluminum silicates,
iron oxides and/or manganese oxides with lower concentrations of calcium
carbonates and calcium sulfates may be suitable. These materials may be
calcined and processed by a number of methods to yield mixtures of
varying compositions and properties.

[0044]A binder may optionally be included for forming an aggregate
composition having desired size, structure, density, porosity and fluid
properties. In addition to, or as an alternative to the use of a binder,
a substrate may be included for providing support to the aggregate
composition. Suitable binder and substrate materials can include any
material that will bind and/or support the insoluble rare
earth-containing compound under conditions of use. Such materials will
generally be included in the aggregate composition in amounts ranging
from about 0 wt % to about 90 wt %, based upon the total weight of the
composition. Suitable materials can include organic and inorganic
materials such as natural and synthetic polymers, ceramics, metals,
carbons, minerals, and clays. One skilled in the art will recognize that
the selection of a binder or substrate material will depend on such
factors as the components to be aggregated, their properties binding
characteristics, desired characteristics of the final aggregate
composition and its method of use among others.

[0045]Suitable polymeric binders can include both naturally occurring and
synthetic polymers, as well as synthetic modifications of naturally
occurring polymers. In general, polymers melting between about 50°
C. and about 500° C., more particularly, between about 75°
C. and about 350° C., even more particularly between about
80° C. and about 200° C., are suitable for use in
aggregating the components of the composition. Non-limiting examples can
include polyolefins that soften or melt in the range from about
85° C. to about 180° C., polyamides that soften or melt in
the range from about 200° C. to about 300° C., and
fluorinated polymers that soften or melt in the range from about
300° C. to about 400° C.

[0046]Depending upon the desired properties of the composition, polymeric
binders can include one or more polymers generally categorized as
thermosetting, thermoplastic, elastomer, or a combination thereof as well
as cellulosic polymers and glasses. Suitable thermosetting polymers
include, but are not limited to, polyurethanes, silicones,
fluorosilicones, phenolic resins, melamine resins, melamine formaldehyde,
and urea formaldehyde. Suitable thermoplastics can include, but are not
limited to, nylons and other polyamides, polyethylenes, including LDPE,
LLDPE, HDPE, and polyethylene copolymers with other polyolefins,
polyvinylchlorides (both plasticized and unplasticized), fluorocarbon
resins, such as polytetrafluoroethylene, polystyrenes, polypropylenes,
cellulosic resins, such as cellulose acetate butyrates, acrylic resins,
such as polyacrylates and polymethylmethacrylates, thermoplastic blends
or grafts such as acrylonitrile-butadiene-styrenes or
acrylonitrile-styrenes, polycarbonates, polyvinylacetates, ethylene vinyl
acetates, polyvinyl alcohols, polyoxymethylene, polyformaldehyde,
polyacetals, polyesters, such as polyethylene terephthalate, polyether
ether ketone, and phenol-formaldehyde resins, such as resols and
novolacs. Suitable elastomers can include, but are not limited to,
natural and/or synthetic rubbers, like styrene-butadiene rubbers,
neoprenes, nitrile rubber, butyl rubber, silicones, polyurethanes,
alkylated chlorosulfonated polyethylene, polyolefins, chlorosulfonated
polyethylenes, perfluoroelastomers, polychloroprene (neoprene),
ethylene-propylene-diene terpolymers, chlorinated polyethylene,
fluoroelastomers, and ZALAK® (Dupont-Dow elastomer). Those of skill in
the art will realize that some of the thermoplastics listed above can
also be thermosets depending upon the degree of cross-linking, and that
some of each may be elastomers depending upon their mechanical
properties. The categorization used above is for ease of understanding
and should not be regarded as limiting or controlling.

[0047]Cellulosic polymers can include naturally occurring cellulose such
as cotton, paper and wood and chemical modifications of cellulose. In a
specific embodiment, the insoluble rare earth-containing compound can be
mixed paper pulp or otherwise combined with paper fibers to form a
paper-based filter comprising the insoluble rare earth-containing
compound.

[0048]Polymer binders can also include glass materials such as glass
fibers, beads and mats. Glass solids may be mixed with particulates of an
insoluble rare earth-containing compound and heated until the solids
begin to soften or become tacky so that the insoluble rare
earth-containing compound adheres to the glass. Similarly, extruded or
spun glass fibers may be coated with particles of the insoluble rare
earth-containing compound while the glass is in a molten or partially
molten state or with the use of adhesives. Alternatively, the glass
composition may be doped with the insoluble rare earth-containing
compound during manufacture. Techniques for depositing or adhering
insoluble rare earth-containing compounds to a substrate material are
described in U.S. Pat. No. 7,252,694 and other references concerning
glass polishing. For example, electro-deposition techniques and the use
of metal adhesives are described in U.S. Pat. No. 6,319,108 as being
useful in the glass polishing art. The descriptions of such techniques
are incorporated herein by reference.

[0049]In some applications such as where a controlled release of the
aggregate composition is desired, water-soluble glasses such as are
described in U.S. Pat. Nos. 5,330,770, 6,143,318 and 6,881,766, may be an
appropriate polymer binder. The descriptions of such glasses in the noted
references are incorporated herein by reference. In other applications,
materials that swell through fluid absorption including but not limited
to polymers such as synthetically produced polyacrylic acids, and
polyacrylamides and naturally-occurring organic polymers such as
cellulose derivatives may also be used. Biodegradable polymers such as
polyethylene glycols, polylactic acids, polyvinylalcohols,
co-polylactideglycolides, and the like may also be used as the polymer
binder.

[0050]Minerals and clays such as bentonite, smectite, kaolin, dolomite,
montmorillinite and their derivatives may also serve as suitable binder
or substrate materials.

[0051]Where it is desirable to regenerate the aggregate composition
through sterilization, the selected binder or substrate material should
be stable under sterilization conditions and should be otherwise
compatible with the sterilization method. Specific non-limiting examples
of polymeric binders that are suitable for sterilization methods that
involve exposure to high temperatures include cellulose nitrate,
polyethersulfone, nylon, polypropylene, polytetrafluoroethylene, and
mixed cellulose esters. Compositions prepared with these binders can be
autoclaved when the prepared according to known standards. Desirably, the
aggregate composition should be stable to steam sterilization or
autoclaving as well as to chemical sterilization through contact with
oxidative or reductive chemical species, as a combination of
sterilization methods may be required for efficient and effective
regeneration. In an embodiment where sterilization includes the
electrochemical generation of an oxidative or reductive chemical species,
the electrical potential necessary to generate said species can be
attained by using the composition as one of the electrodes. For example,
a composition that contains a normally insulative polymeric binder can be
rendered conductive through the inclusion of a sufficiently high level of
conductive particles such as granular activated carbon, carbon black, or
metallic particles. Alternatively, if the desired level of carbon or
other particles is not sufficiently high to render an otherwise
insulative polymer conductive, an intrinsically conductive polymer may
included in the binder material. Various glasses such as microporous
glass beads and fibers are particularly suited for use as a substrate or
binder where the composition is to be periodically regenerated.

[0052]Other optional components of the aggregate composition can include
additives, such as particle surface modification additives, coupling
agents, plasticizers, fillers, expanding agents, fibers, antistatic
agents, initiators, suspending agents, photosensitizers, lubricants,
wetting agents, surfactants, pigments, dyes, UV stabilizers, and
suspending agents. The amounts of these materials are selected to provide
the properties desired. Such additives may be incorporated into a binder
or substrate material, applied as a separate coating, held within the
structure of the aggregate composition, or combinations of the above.

[0053]The aggregate composition can be formed though one or more of
extrusion, molding, calcining, sintering, compaction, the use of a binder
or substrate, adhesives and/or other techniques known in the art. It
should be noted that neither a binder nor a substrate is required in
order to form the aggregate composition although such components may be
desired depending on the intended application. In embodiments where the
aqueous solution is to be flowed through a bed of the aggregate
composition, the composition can incorporate a polymer binder so that the
resulting composition has both high surface area and a relatively open
structure. Such an aggregate composition maintains elevated activity for
removing or detoxifying chemical contaminants without imposing a
substantial pressure drop on the treated solution. In embodiments where
it is desired that the aggregate composition have higher surface areas,
sintering is a less desirable technique for forming the aggregate
composition. When the insoluble rare earth-containing compound has been
sintered to form the aggregate composition, the composition will contain
no more than two elements selected from the group consisting of yttrium,
scandium, and europium.

[0054]In one embodiment, the aggregate composition can be produced by
combining an insoluble rare earth-containing compound or a calcined
aggregate of an insoluble rare earth-containing compound with a binder or
substrate such as a polyolefin, cellulose acetate,
acrylonitrile-butadiene-styrene, PTFE, a microporous glass or the like.
The insoluble rare earth-containing compound, preferably in the form of a
high surface area particulate, is mixed with the solid binder material.
The mixture is then heated to a temperature, such as the glass transition
temperature of the binder material, at which the solid binder material
softens or becomes tacky. Depending on the temperature required to
achieve a softened or tacky binder, the mixture may be heated at elevated
pressure(s). The mixture is then allowed to cool so that mixture forms an
aggregate with the insoluble rare earth-containing particulate adhered to
the binder.

[0055]Where glass fibers or beads are used as a binder or substrate, the
glass solids may be mixed with particulates of an insoluble rare
earth-containing compound and heated until the glass begins to soften or
become tacky so that the insoluble rare earth-containing adheres to the
glass upon cooling. Alternatively, the glass composition may be doped
with the insoluble rare earth-containing compound during manufacture of
the glass solids. Other techniques for depositing or adhering insoluble
rare earth-containing compounds to a substrate are described in U.S. Pat.
No. 7,252,694 and other references concerning glass polishing. For
example, electro-deposition techniques and the use of metal adhesives are
described in U.S. Pat. No. 6,319,108 as being useful in the glass
polishing art. The descriptions of such techniques are incorporated
herein by reference.

[0056]Those familiar with the art of fluid treatment will understand that
the components, physical dimensions and shape of the aggregate
composition may be manipulated for different applications and that
variations in these variables can alter flow rates, back-pressure, and
the capacity of the composition to remove or detoxifying chemical
contaminants. As a result, the size, form and shape of the aggregate
composition can vary considerably depending on the method of use. Where
the aqueous solution is to be flowed through the aggregate composition,
such as in a column or other container, it desired that the aggregate
composition have relatively open structure, with channels or pores that
provide a high degree of fluid permeability and/or low density.

[0057]The aggregate composition can comprise aggregated particulates in
granule, bead, powder, fiber or similar form. Such aggregated
particulates can have a mean aggregate size of at least about 1 μm,
specifically at least about 5 μm, more specifically at least about 10
μm, and still more specifically at least about 25 μm. In other
embodiments, the aggregate will have a mean aggregate size of at least
about 0.1 mm, specifically at least about 0.5 mm, more specifically at
least about 1 mm, still more specifically at least about 2 mm, and yet
still more specifically more than 5.0 mm. The aggregate composition can
be crushed, chopped or milled and then sieved to obtain the desired
particle size. Such aggregated particulates can be used in fixed or
fluidized beds or reactors, stirred reactors or tanks, distributed in
particulate filters, encapsulated or enclosed within membranes, mesh,
screens, filters or other fluid permeable structures, deposited on filter
substrates, and may further be formed into a desired shape such as a
sheet, film, mat or monolith for various applications.

[0058]In addition, the aggregate composition can be incorporated into or
coated onto a substrate. Suitable substrates can be formed from the
described binder and substrate materials such as sintered ceramics,
sintered metals, microporous carbon, glass fibers and beads, and
cellulosic fibers such as cotton, paper and wood. The structure of the
substrate will vary depending upon the application but can include woven
and non-wovens in the form of a porous membrane, filter or other fluid
permeable structure. Substrates can also include porous and fluid
permeable solids having a desired shape and physical dimensions. Such
substrates can include mesh, screens, tubes, honeycombed structures,
monoliths and blocks of various shapes including cylinders and toroids.
In a particular embodiment, the aggregate composition and can be
incorporated into or coated onto a filter block or monolith for use in
cross-flow type filter.

[0059]The aggregate composition is used to treat an aqueous solution
containing a chemical contaminant by contacting the solution with the
composition. Contact between the solution and the composition can be
achieved by flowing the solution through the composition or by adding the
composition to the solution, with or without mixing or agitation. If the
aqueous solution is to be treated with air, oxygen-enriched air, ozone or
hydrogen peroxide for the purpose of wet oxidizing fungi, viruses or
other biological contaminants in the solution, then the aqueous solution
is contacted with the aggregate composition prior to any such treatment
with air, oxygen-enriched air, ozone or hydrogen peroxide. Contact with
the aggregate composition is sufficient to remove or deactivate
biological contaminants in the solution and the treatment of the aqueous
solution with ozone or other agents for the purpose of wet oxidizing
contaminants in solution is purely optional in nature.

[0060]In some embodiments, the aggregate composition is distributed over
the surface of a solution and allowed to settle through the solution
under the influence of gravity. Such an application is particularly
useful for reducing chemical contaminants in solutions found in
evaporation tanks, municipal water treatment systems, fountains, ponds,
lakes and other natural or man-made bodies of water. In such embodiments,
it is preferred but not required that the composition be filtered or
otherwise separated from the solution for disposal or regeneration and
re-use.

[0061]In other embodiments, the aggregate composition can be introduced
into the flow of the aqueous solution such as through a conduit, pipe or
the like. Where it is desirable to separate the treated solution from the
composition, the aggregate composition is introduced into the solution
upstream of a filter where the composition can be separated and recovered
from the solution. A particular example of such an embodiment can be
found in a municipal water treatment operations where the composition is
injected into the water treatment system upstream of a particulate filter
bed.

[0062]In other embodiments, the aggregate composition can be disposed in a
container and the solution directed to flow through the composition. The
aqueous solution can flow through the composition under the influence of
gravity, pressure or other means and with or without agitation or mixing.
In still other embodiments, the container can comprise a fluid permeable
outer wall encapsulating the aggregate composition so that the solution
has multiple flow paths through the composition when submerged. Various
fittings, connections, pumps, valves, manifolds and the like can be used
to control the flow of the solution through the composition in a given
container.

[0063]The aqueous solution contacts the aggregate composition at a
temperature above the triple point for the solution. In some cases, the
solution contacts the composition at a temperature less than about
100° C. and in other cases, contact occurs at a temperature above
about 100° C., but at a pressure sufficient to maintain at least a
portion of the aqueous solution in a liquid phase. The composition is
effective at removing and detoxifying chemical contaminants at room
temperatures. In other cases, the aqueous solution contacts the
composition under supercritical conditions of temperature and pressure
for the aqueous solution.

[0064]The pressure at which the aqueous solution contacts the aggregate
composition can vary considerably depending on the application. For
smaller volume applications where the contact is to occur within a
smaller diameter column at a flow rates less than about 1.5 gpm, the
pressure can range from 0 up to about 6.0 psig. In applications where
larger containers and higher flow rates are employed, higher pressures
may be required.

[0065]After contacting the aqueous solution, the aggregate composition may
contain active and deactivated biological contaminants. As a result, it
may be advantageous to sterilize the composition before re-use or
disposal. Moreover, it may be desirable to sterilize the composition
prior to contacting the aqueous solution to remove any contaminants that
may be present before use. Sterilization processes can include thermal
processes wherein the composition is exposed to elevated temperatures or
pressures or both, radiation sterilization wherein the composition is
subjected to elevated radiation levels, including processes using
ultraviolet, infrared, microwave, and ionizing radiation, and chemical
sterilization, wherein the composition is exposed to elevated levels of
oxidants or reductants or other chemical species. Chemical species that
may be used in chemical sterilization can include halogens, reactive
oxygen species, formaldehyde, surfactants, metals and gases such as
ethylene oxide, methyl bromide, beta-propiolactone, and propylene oxide.
Combinations of these processes can also be used and it should further be
recognized that such sterilization processes may be used on a sporadic or
continuous basis while the composition is in use.

[0066]The process can optionally include the step of sensing the solution
depleted of chemical contaminants so as to determine or calculate when it
is appropriate to replace the composition. Sensing of the solution can be
achieved through conventional means such as tagging and detecting the
contaminants in the aqueous solution using fluorescent or radioactive
materials, measuring flow rates, temperatures, pressures, sensing for the
presence of fines, and sampling and conducting arrays. Techniques used in
serology testing or analysis may also be suitable for sensing the
solution depleted of chemical contaminants.

[0067]The process can optionally include separating the solution depleted
of chemical contaminants from the composition. The composition can be
separated from the solution by conventional liquid-solid separation
techniques including, but not limited to, the use of filters, membranes,
settling tanks, centrifuges, cyclones or the like. The separated solution
depleted of active biological contaminants can then be directed to
further processing, storage or use.

[0068]In another embodiment, the invention is directed to an apparatus for
treating an aqueous solution containing a chemical contaminant. The
apparatus comprises a container having a fluid flow path and an aggregate
composition as described herein disposed in the fluid flow path.
Specifically, the aggregate composition comprises more than 10.01% by
weight of tile insoluble rare earth-containing compound and comprises no
more than two elements selected from the group consisting of yttrium,
scandium, and europium when the aggregate composition is sintered.
Details of the aggregate composition are described elsewhere herein and
are not repeated here.

[0069]The container can take a variety of forms including columns, various
tanks and reactors, filters, filter beds, drums, cartridges, fluid
permeable containers and the like. In some embodiments, the container
will include one or more of a fixed bed, a fluidized bed, a stirred tank
or reactor, or filter, within which the aqueous solution will contact the
composition. The container can have a single pass through design with a
designated fluid inlet and fluid outlet or can have fluid permeable outer
wall enclosing or encapsulating the aggregate composition. Where it is
desired that the container be flexible in nature, the fluid permeable
outer wall can be made from woven or non-woven fabric of various
wafer-insoluble materials so that the aqueous solution has multiple flow
paths through the composition when submerged. Where a more rigid
structure is preferred, the container can be manufactured from metals,
plastics such as PVC or acrylic, or other insoluble materials that will
maintain a desired shape under conditions of use.

[0070]The aqueous solution can flow through the composition and container
under the influence of gravity, pressure or other means, with or without
agitation or mixing. Various fittings, connections, pumps, valves,
manifolds and the like can be used to control the flow of the solution
into the container and through the composition.

[0071]The container can be adapted to be inserted into and removed from an
apparatus or process stream to facilitate use and replacement of the
composition. Such a container can have an inlet and outlet that are
adapted to be sealed when removed from the apparatus or when otherwise
not in use to enable the safe handling, transport and storage of the
container and composition. Where the aggregate composition is to be
periodically sterilized, the composition and container may be removed and
sterilized as a unit, without the need to remove the composition from the
container. In addition, such a container may also be constructed to
provide long term storage or to serve as a disposal unit for chemical
contaminants removed from the solution.

[0072]The apparatus can include a filter for separating the treated
solution from the composition. The filter can encapsulate the aggregate
composition or be disposed downstream of the composition. Moreover, the
filter can be a feature of the container for preventing the composition
from flowing out of the container or be a feature of the apparatus
disposed downstream of the container. The filter can include woven and
non-woven fabrics, mesh, as well as fibers or particulates that are
disposed in a mat, bed or layer that provides a fluid permeable barrier
to the aggregate composition. Where the aggregate composition is disposed
in a fixed bed, a suitable filter can include a layer of diatomaceous
earth disposed downstream of the composition within the container.

[0073]The apparatus may also optionally include one or more of a visual
indicator for indicating when the composition should be replaced or
regenerated, a sensor for sensing an effluent flowing out of the
container, and means for sterilizing the composition. Means for
sterilizing the composition can include one or more of means for heating
the composition, means for irradiating the composition and means for
introducing a chemical oxidation agent into the fluid flow path, such as
are known in the art.

[0074]In yet another embodiment, the invention provides an article
comprising a container having one or more walls defining an interior
space and a flowable aggregate composition disposed in the interior
space. As described in detail elsewhere herein, the aggregate composition
comprises more than 10.01% by weight of an insoluble rare
earth-containing compound and comprises no more than two elements
selected from the group consisting of yttrium, scandium, and europium
when the aggregate has been sintered. In addition, the container bears
instructions for use of the aggregate composition to treat an aqueous
solution containing a chemical contaminant. In this particular
embodiment, the container is a bag or other bulk product package in which
the flowable aggregate composition may be marketed or sold to retailers,
distributors or end use consumers. Such containers can take a variety of
sizes, shapes, and forms, but are typically made from plastics or various
fabrics. The container bears an instruction indicating that the contents
of the container can be effectively used to treat aqueous solutions
containing a chemical contaminant such as for the purpose of removing or
detoxifying such a contaminant in the solution.

[0075]The following examples are provided to demonstrate particular
embodiments of the present invention. It should be appreciated by those
of skill in the art that the methods disclosed in the examples which
follow merely represent exemplary embodiments of the present invention.
However, those of skill in the art should, in light of the present
disclosure, appreciate that many changes can be made in the specific
embodiments described and still obtain a like or similar result without
departing from the spirit and scope of the present invention.

EXAMPLE

[0076]ABS plastic filter housings (1.25 inches in diameter and 2.0 inches
in length) were packed with ceric oxide (CeO2) that was prepared
from the thermal decomposition of 99% cerium carbonate. The housings were
sealed and attached to pumps for pumping an aqueous solution through the
housings. The aqueous solutions were pumped through the material at flow
rates of 50 and 75 ml/min. A gas chromatograph was used to measure the
final content of the chemical contaminant. The chemical contaminants
tested, their initial concentration in the aqueous solutions, and the
percentage removed from solution are presented in Table 1.

[0077]The particular embodiments disclosed above are illustrative only, as
the invention may be modified and practiced in different but equivalent
manners apparent to those skilled in the art having the benefit of the
teachings herein. Furthermore, no limitations are intended to the details
of construction or design herein shown, other than as described in the
claims below. It is therefore evident that the particular embodiments
disclosed above may be altered or modified and all such variations are
considered within the scope and spirit of the invention. Accordingly, the
protection sought herein is as set forth in the claims below.